In ergonomics, physical exertion (e.g. work) is studied to try to reduce user fatigue and discomfort. As an individual exerts physical effort, physiological and biomechanical factors interweave. Physiologically, the human structures of ergonomic issue are skeletal and muscular. Individuals of differing shoulder breadth, for example, will position somewhat differently over a same-size keyboard. Biomechanically, components of ergonomic issue include posture, force, repetition and vibration. An upright sitting posture while manipulating a pointing device, for example, engenders different body exertion than a slouching posture.
Posture ranks right up at the top of the list when you are talking about good health. It is as important as eating right, exercising, getting a good night's sleep and avoiding potentially harmful substances like alcohol, drugs and tobacco. Good posture is a way of doing things with more energy, less stress and fatigue. Without good posture, a person's overall health and total efficiency may be compromised. Because the long-term effects of poor posture can affect bodily systems (such as digestion, elimination, breathing, muscles, joints and ligaments), a person who has poor posture may often be tired or unable to work efficiently or move properly.
Poor posture could bring on more severe musculoskeletal disorders (MSDs) such as ruptured disc or carpal tunnel syndrome. Excessive loading of the back musculoskeletal structures could weaken and even rupture a spinal disc. Carpal tunnel syndrome is normally caused by repetitive use of a hand or a wrist, where posture of the larger musculoskeletal structures (neck, arm) and/or finer structures (wrist, fingers) affects loading.
MSDs can happen to anyone who exerts repeated physical effort over periods of time. Stressful wrist, arm, neck and/or back positions, whether from working at a desk, long distance driving or lifting boxes, only aggravate the potential for damage.